The GraphicsTerrain portion in my client memory is taking up around 40 MB, however the game has little terrain. When I delete the terrain, I still have 37 MB, and even more curiously, if I delete the Terrain part in Workspace I end up with 3 MB of terrain.
Does this mean I have invisible terrain that hasn’t been deleted? I can’t see anything even after deleting everything but terrain in the world.
Any help is appreciated.
To clarify, my visible terrain accounts for only 3 MB of the 40, so this is a big confusion.
Maybe air is considered part of terrain? Idk, just a theory
I don’t think so since when I was working on the game a few months ago the terrain was much lower
I think this is because, if you have, there is an lightning image on. I don’t watch that MB thing if I have enough or that I ran out but I think it’s lighting or script in serverscriptsetvice
I’d need engineering to confirm this, but it feels like there’s some level of Instancing going on with Terrain?
Starting a new Studio session with no terrain resulted in GraphicsTerrain = 0mb, as a control.
Then I added in a little blob of terrain, jumping GraphicsTerrain to just under 36mb.
Then I added a very large field of terrain beside the initial blob, and it only jumped to 49mb.
What this suggests to me (I’m not ruling out other causes), is that similar to how Instancing works with regards to MeshParts (the first meshpart causes the load, all other copied meshparts are much less performance costly), there’s an initial jump in performance cost for the first time terrain is placed, but all subsequent use of terrain is less costly.
What I do not understand is the performance cost sticking around after terrain is removed. I used the Terrain plugin’s Clear tool which clears all terrain, and I still have 35mb of usage hanging around.
I will caveat all of this to say that I’m doing this all in Studio Test, which I know has a few inaccuracies with memory usage.
I will note, however, that in World//Zero, one of our more terrain-complex maps is only using 126mb total of terrain and running generally fine even on mobile. If you’re concerned about the performance cost of terrain (outside of an ocean of water), I’d suggest other avenues of performance optimization 
Thank you for testing out my issue.
What I do not understand is the performance cost sticking around after terrain is removed. I used the Terrain plugin’s Clear tool which clears all terrain, and I still have 35mb of usage hanging around.
Yeah that’s exactly the issue. Performance isn’t dropping but I’m not sure where those ‘invisible’ MB go towards, since all the terrain is gone.
I have, however, tested this outside of studio and I get the same results (ghost 37 MB still hanging around). If there’s a hidden reason for this that you found out I’d love to know, thanks
